diff --git a/gulpfile.js b/gulpfile.js
index 3d5c55a9bc..a36bf62510 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -8,13 +8,14 @@ const gulp = require('gulp'),
     zip = require('gulp-zip'),
     manifest = require('./src/manifest.json'),
     xmlpoke = require('gulp-xmlpoke'),
-    del = require('del');
+    del = require('del'),
+    fs = require('fs');
 
 const paths = {
     build: './build/',
     dist: './dist/',
     coverage: './coverage/',
-    npmDir: './node_modules/',
+    node_modules: './node_modules/',
     popupDir: './src/popup/',
     cssDir: './src/popup/css/'
 };
@@ -217,6 +218,13 @@ function copy(source, dest) {
     });
 }
 
+// ref: https://github.com/t4t5/sweetalert/issues/890
+function fixSweetAlert(cb) {
+    fs.writeFileSync(paths.node_modules + 'sweetalert/typings/sweetalert.d.ts',
+        'import swal, { SweetAlert } from "./core";export default swal;export as namespace swal;');
+    cb();
+}
+
 exports['dist:firefox'] = distFirefox;
 exports['dist:chrome'] = distChrome;
 exports['dist:opera'] = distOpera;
@@ -227,3 +235,5 @@ exports['ci:coverage'] = ciCoverage;
 exports.ci = ciCoverage;
 exports.webfonts = webfonts;
 exports.build = webfonts;
+exports.fixSweetAlert = fixSweetAlert;
+exports.postinstall = fixSweetAlert;
diff --git a/package-lock.json b/package-lock.json
index 05c69fb4e0..672e6b9427 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4465,8 +4465,7 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -4487,14 +4486,12 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -4509,20 +4506,17 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -4639,8 +4633,7 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "ini": {
           "version": "1.3.5",
@@ -4652,7 +4645,6 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -4667,7 +4659,6 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -4675,14 +4666,12 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "minipass": {
           "version": "2.2.4",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.1",
             "yallist": "^3.0.0"
@@ -4701,7 +4690,6 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -4782,8 +4770,7 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -4795,7 +4782,6 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -4881,8 +4867,7 @@
         "safe-buffer": {
           "version": "5.1.1",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -4918,7 +4903,6 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -4938,7 +4922,6 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
-          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -4982,14 +4965,12 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         },
         "yallist": {
           "version": "3.0.2",
           "bundled": true,
-          "dev": true,
-          "optional": true
+          "dev": true
         }
       }
     },
@@ -11526,9 +11507,9 @@
       }
     },
     "sweetalert": {
-      "version": "2.1.0",
-      "resolved": "https://registry.npmjs.org/sweetalert/-/sweetalert-2.1.0.tgz",
-      "integrity": "sha512-9YKj0SvjKyBfRWco50UOsIbXVeifYbxzT9Qda7EsqC01eafHGCSG0IR7g942ufjzt7lnwO8ZZBwr6emXv2fQrg==",
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/sweetalert/-/sweetalert-2.1.2.tgz",
+      "integrity": "sha512-iWx7X4anRBNDa/a+AdTmvAzQtkN1+s4j/JJRWlHpYE8Qimkohs8/XnFcWeYHH2lMA8LRCa5tj2d244If3S/hzA==",
       "requires": {
         "es6-object-assign": "^1.1.0",
         "promise-polyfill": "^6.0.2"
diff --git a/package.json b/package.json
index 33127fe605..7e3fbfcb74 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,7 @@
     "sub:init": "git submodule update --init --recursive",
     "sub:update": "git submodule update --remote",
     "sub:pull": "git submodule foreach git pull",
-    "postinstall": "npm run sub:init",
+    "postinstall": "npm run sub:init && gulp postinstall",
     "build": "gulp build && webpack",
     "build:watch": "gulp build && webpack --watch",
     "build:prod": "gulp build && cross-env NODE_ENV=production webpack",
@@ -98,7 +98,7 @@
     "node-forge": "0.7.6",
     "papaparse": "4.6.0",
     "rxjs": "6.3.3",
-    "sweetalert": "2.1.0",
+    "sweetalert": "2.1.2",
     "tldjs": "2.3.1",
     "web-animations-js": "2.3.1",
     "zone.js": "0.8.28",